Why the Pentagon’s ‘killer robots’ are spurring major concerns

As the Defense Department is pushing aggressively to modernize its forces using fully autonomous drones and weapons systems, critics fear the start of a new arms race that could dramatically raise the risk of mass destruction, nuclear war and civilian casualties.

The Pentagon and military tech industry are going into overdrive in a massive effort to scale out existing technology in what has been the Replicator initiative. It envisions a future force in which fully autonomous systems are deployed in flying drones, aircraft, water vessels and defense systems — connected...